The desire to maintain a youthful appearance by preventing or reducing wrinkles in the skin is an important issue in human society. Many techniques have been designed to achieve the above goal. One of the techniques is to damage part of the dermis of the skin in order to induce the formation of connective tissue and new epidermis of the skin. Document U.S. Pat. No. 5,964,749 discloses a method and apparatus for wrinkle smoothing by applying pulsed light to the skin to heat and shrink collagen. In certain embodiments, light with a wavelength in the range of 600-1200 nm is applied, in the form of pulses, and with fluences of about 100 J/cm2. Preferably, the epidermis is cooled.
A disadvantage of the disclosed method and the corresponding apparatus is that it has a high risk of damaging the epidermis, because all energy is provided non-discriminately. Damage to the epidermis is highly undesirable because this may lead to complications and health risks to the person being treated.